 SIYG.TXT       Glossary of Surveying Words                    72


                            Chapter G


                   Glossary of Surveying Words


Abney level: A hand held instrument for measuring inclination
precise to about 0.2 degrees.  There are several manufacturers.
Cost about $75 to $150.

Acre: 10 square chains.  43560 square feet.

Aerial photo: A photograph taken straight down from a high
altitude airplane so that the photo looks like a map.

Are: Pronounced "air".  100 square meters.

Azimuth: The common method of giving compass directions, whereby
a full circle is divided into 360 degrees, starting at North and
turning clockwise.  I'm told that this doesn't apply in the
Southern Hemisphere.

Backsight: Instrument readings taken to the FROM station, from
the TO station, but recorded as if the sight were taken normally.

Blunder: A BIG mistake, obvious and correctable.

Brunton pocket transit: A sighting compass precise to about 0.5
degree.  Brunton makes the original; there are several
imitators.  Also known as Army Artillery Compass when graduated
in gradians to confound The Enemy.  Cost: about $200.

Cardinal direction: Any one of the four directions; North, East,
South, or West.

Chain: 66 feet.  4 rods.

Clinometer: Inclinometer.  A device to measure inclination.

Closure Error: When surveying in a loop and making the ending
station the same as the beginning station, the calculated
distance between these two stations.

Compass direction: A direction from one station to another
station, measured as azimuth.


 SIYG.TXT       Glossary of Surveying Words                   73


Corner: A point on a property boundary, established to define
that boundary.

Cosine: Abbr.  COS.  Pronounced "cosign".  A mathematical
function of an angle, equal to the adjacent side divided by the
hypotenuse (longest side) of a right triangle containing that
angle.

Declination: The angle difference between the compass direction
towards Magnetic North and that towards True North.

Degree: The three hundred sixtieth part of a full circle.
1 = 1/360 of a turnaround.

Departure: What professional surveyors call the east distance.

Elevation: The distance above (or below) an arbitrary zero level.

Error: The difference between a measured value and reality.

Forester's Compass: Staff Compass.  A surveying compass precise
to about 0.2 degrees.  Cost: $400.

Furlong: 10 chains.  660 feet.

Gradians: A method of giving compass directions, whereby a full
circle is divided into 400 gradians, starting at North and
turning clockwise.  The Army uses this to confuse The Enemy.

Hectare: 100 ares.  10000 square meters.  2.47 acres.

Inclination: The angle in degrees between a line of sight and
horizontal.  Up is +, down is -.

Inclinometer: Clinometer.  An instrument to measure inclination.

Land description: The written definition of a piece of property.

Latitude: What professional surveyors call the north distance.

Legal description: A land description typed by an attorney's
secretary.

Lensatic compass: Also known as the Army Marching Compass.  A
diabolically engineered compass graduated in bassackwards
whatchamacallits in order to totally confuse The Enemy.  Precise
to about 10 degrees.  Cost: about $10.
 SIYG.TXT       Glossary of Surveying Words                   74


Line: A part of a property boundary between two corners.

Link: A hundredth part of a chain, 0.66 feet.

Magnetic North: The direction towards the Magnetic North Pole.
This is where the compass needle points.

Minute: The sixtieth part of a degree.  1' = 1/60  60' = 1

Pace: The distance covered in one step.  Usually between 2.5 and
3.0 feet.  1000 double paces of 2.64 feet define the mile as 5280
feet.

Perch: A rod, a pole, 16.5 feet.

Percent closure error: The closure error divided by the run
times 100%.

Plat: What professional surveyors call a map.

Pole: A rod, a perch, 16.5 feet.

Quadrants: An archaeic method of giving compass directions,
utilized to simplify the arithmetic B.C.  [Before Calculator]
Presently used to keep landowners stupid.

Radians: A mathematical method of measuring angles, used by some
calculators, computers, and pure mathematicians.  A Radian =
57.2957795131 degrees.

Ranger: A sighting compass imported by Silva Compass, precise to
about 1 degree.  Cost: about $41.

Rod: A perch, a pole, 16.5 feet.

Rood: 40 square rods, perches or poles.  10890 square feet,
one quarter acre.

Rope: 20 feet.

Run: The distance surveyed since an arbitrary starting station.

Second: The sixtieth part of a minute. 1" = 1/60'  60" = 1'

Sine: Abbr.  SIN.  Pronounced "sign".  A mathematical function of
an angle, equal to the opposite side divided by the hypotenuse
(longest side) in a right triangle containing that angle.
 SIYG.TXT       Glossary of Surveying Words                   75


Square perch: A square rod, 16.5 * 16.5 = 272.25 square feet.

Staff Compass: Forester's Compass.  A surveying compass precise
to about 0.2 degrees.  Cost: $400.

Station: A place where surveyor's measurements are taken.

Stringbox: A distance measuring instrument which operates by
measuring a thread pulled from it.

Tape distance: A distance from one station to another, usually
measured in feet.

Theodolite: A surveying instrument which can measure the angle
between two directions, as well as the angle between a direction
and Magnetic North.  Precision: about 0.01 degree.  Cost:
$thousands.

Topo map, topographic map: A map showing the shape of the surface
of the land.  In the United States, usually a 7.5 minute map at
2000 feet per inch showing all surface features.  Cost: about $3.

Transit: A surveying instrument, similar to a theodolite, which
can measure the angle between two directions, as well as the
angle between a direction and Magnetic North.  Additionally, the
sights can be easily turned around (transited) to obtain a
backsight.  Precision: about 0.01 degree.  Cost: $thousands.

True North: The direction towards the North Pole.

: Degree symbol if you can read full ASCII.

': Minute symbol.  Also foot symbol.

": Second symbol.  Also inch symbol.

Another last chance to tell you to take precise compass readings,
with a double check and a backsight.  Nearly all your error is in
the compass with the poor man's method of land surveying.

If there are any other surveying words which you think that I
should define here, then tell me them.

Copyright (c)1994 by David Perry Beiter

If you have any questions, problems, or comments, write or call
me. Dave Beiter, CAVE Inc, 1/2 Fast Road, Ritner KY 42639.
606/376-3137.  MCI Mail: 635-1762  byter@mcimail.com
 SIYG.TXT       Glossary of Surveying Words                   76


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